The present invention relates to a socket of a discharge lamp bulb. More particularly, the present invention relates to a technique for avoiding discharging between supply terminals by power supply where the socket is not connected to or incompletely connected to the discharge lamp bulb.
In recent years, a discharge lamp bulb has been used as a light source of a head light for a motor vehicle.
In the case of such a discharge lamp bulb, a socket for the discharge lamp bulb is located between a starting circuit and the discharge lamp bulb.
In the discharge lamp described, a high starting voltage is supplied between power supply terminals for a discharge lamp bulb. Therefore, with the power supply terminal not surely connected to the terminals of the discharge lamp bulb, i.e. a socket for the discharge lamp bulb not fixed to a normal connecting position relative to the discharge lamp bulb, when a starting voltage is supplied, discharge occurs between the supply terminals. This may lead to a problem of damaging the socket for the discharge lamp bulb, the discharge lamp bulb or both thereof.
The present invention intends to avoid discharging between power supply terminals where a socket for the discharge lamp bulb is not fixed to the normal connecting position relative to a discharge lamp bulb.